test: fix mishandling of "test '(' = '('" and similar

function                                             old     new   delta
test_main                                            246     350    +104

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 35 insertions, 34 deletions

diff --git a/coreutils/test.c b/coreutils/test.c
index 4df505a05..88cc55050 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -826,7 +826,6 @@ int test_main(int argc, char **argv)
 {
         int res;
         const char *arg0;
-//      bool negate = 0;
 
         arg0 = bb_basename(argv[0]);
         if (arg0[0] == '[') {
@@ -844,6 +843,7 @@ int test_main(int argc, char **argv)
                 }
                 argv[argc] = NULL;
         }
+        /* argc is unused after this point */
 
         /* We must do DEINIT_S() prior to returning */
         INIT_S();
@@ -862,43 +862,45 @@ int test_main(int argc, char **argv)
          */
         /*ngroups = 0; - done by INIT_S() */
 
-        //argc--;
         argv++;
+        args = argv;
 
-        /* Implement special cases from POSIX.2, section 4.62.4 */
-        if (!argv[0]) { /* "test" */
-                res = 1;
-                goto ret;
-        }
-#if 0
-// Now it's fixed in the parser and should not be needed
-        if (LONE_CHAR(argv[0], '!') && argv[1]) {
-                negate = 1;
-                //argc--;
-                argv++;
-        }
-        if (!argv[1]) { /* "test [!] arg" */
-                res = (*argv[0] == '\0');
-                goto ret;
-        }
-        if (argv[2] && !argv[3]) {
-                check_operator(argv[1]);
-                if (last_operator->op_type == BINOP) {
-                        /* "test [!] arg1 <binary_op> arg2" */
-                        args = argv;
-                        res = (binop() == 0);
-                        goto ret;
+        /* Implement special cases from POSIX.2, section 4.62.4.
+         * Testcase: "test '(' = '('"
+         * The general parser would misinterpret '(' as group start.
+         */
+        if (1) {
+                int negate = 0;
+ again:
+                if (!argv[0]) {
+                        /* "test" */
+                        res = 1;
+                        goto ret_special;
+                }
+                if (!argv[1]) {
+                        /* "test [!] arg" */
+                        res = (argv[0][0] == '\0');
+                        goto ret_special;
+                }
+                if (argv[2] && !argv[3]) {
+                        check_operator(argv[1]);
+                        if (last_operator->op_type == BINOP) {
+                                /* "test [!] arg1 <binary_op> arg2" */
+                                args = argv;
+                                res = (binop() == 0);
+ ret_special:
+                                /* If there was leading "!" op... */
+                                res ^= negate;
+                                goto ret;
+                        }
+                }
+                if (LONE_CHAR(argv[0], '!')) {
+                        argv++;
+                        negate ^= 1;
+                        goto again;
                 }
         }
 
-        /* Some complex expression. Undo '!' removal */
-        if (negate) {
-                negate = 0;
-                //argc++;
-                argv--;
-        }
-#endif
-        args = argv;
         res = !oexpr(check_operator(*args));
 
         if (*args != NULL && *++args != NULL) {
@@ -911,6 +913,5 @@ int test_main(int argc, char **argv)
         }
  ret:
         DEINIT_S();
-//      return negate ? !res : res;
         return res;
 }